The present invention relates generally to apparatus for setting or securing parts of a fractured bone and particularly to apparatus and methods for securing parts of fractured bones such as the phalanges, metacarpals, and metatarsals. Still more particularly, this invention relates to a device for insertion into the medullary cavity of fractured phalanges, metacarpals, and metatarsals to secure the parts together.
It is a known medical procedure to secure the parts of broken bones together by inserting a portion of a rod or tube inside the medullary cavity of one part of the broken bone and then inserting the remainder of the rod or tube inside the medullary cavity of the second portion of the broken bone. Since the phalanges, metacarpals and metatarsals are relatively short bones and, accordingly, difficult to secure with splints or casts, the use of an implanted rod or tube is useful in healing fractures of such bones.
However, a shortcoming of prior techniques for implanting a rod or tube inside the medullary cavity of bones such as the phalanges is the difficulty encountered in securing the rod inside the medullary cavity to retain the fractured portions in contact so that healing may occur.
Prior intramedullar rods generally require drilling of the bone to provide a cavity of suitable shape and dimensions for receiving a rod. Both the rod and the drilled cavity are generally cylindrical so that engagement of the rod in the cavity affords minimal retention against relative axial and rotational movement of the parts of the fractured bone. The necessity of drilling the medullary cavity of the broken bone makes the setting procedure excessively time consuming, which may result in excessive trauma to a patient who has already suffered a serious injury.